1. Field of the Invention
The present invention relates to a video control apparatus and a video control method which measure an influence on an organism by a video and control the video based on acquired data.
2. Description of the Related Art
In recent years, an increase in screen size and an enhancement in colorfulness in a video display apparatus has progressed, and a large number of viewers can enjoy videos having the sense of presence. While viewers have enjoyed videos, there have been reports of videos having a bad influence on an organism. For example, when a video photographed by means of a commercially-available video camera and having a camera shake is viewed through a large screen display, some viewers exhibit symptoms similar to motion sickness, that is, they have a discomfort which is referred to as a “visually induced motion sickness”. In this scenario, the viewer has a feeling that the viewer is moving in a visual space through a video on a large screen which is being viewed while the viewer is stationary. Consequently, an inconsistency is made between a visual perception obtained from an optic organ and a sense of balance obtained from a vestibular organ so that a spatial cognition in the viewer's brain is hindered. In this condition, body control is impeded. The “visually induced motion sickness” is an example in which a component related to a motion in a video badly influences an organism.
While in some circumstances video has had unfavorable influences on organisms, in other circumstances, video has had favorable influences on organisms. For example, for infants, it is effective to view a video as a training for perceiving a visual stimulus, for example, a color, a shape or a motion. However, it is hard for an infant to express its own visual performance in a language. For this reason, it is difficult to evaluate whether a video which is being viewed is really perceived by the infant. Even if a mechanism for perceiving a motion of a video displays a video including a target moving at a high speed is displayed for an undeveloped infant, there is a possibility that the target might not be perceived and an advantage of the video might not be obtained. Therefore, the evaluation is hard to perform. For the purpose of promoting a development of the visual system of the infant, it is necessary to control a motion in a video at such a speed that the infant can perceive the motion. In consideration of the circumstances, there has been desired a technique for objectively detecting an influence of a video on an organism and controlling a video to be displayed for a viewer depending on the situation.
As the technique for changing a display condition, such as a display size or a resolution corresponding to a work progressing state of a user of a display apparatus or a fatigue situation corresponding thereto, and reducing the load on the organism of the user, Japanese Patent Application Laid-Open No. 2004-191628 discusses a display system and a display method which use organism-specific information. This system and method controls a display size of a character or an image, or a resolution or a display position, based on measured data on organism-specific information such as brain waves, respiration, a pulse, or blood pressure generated from an organism. The data reflecting a state of a user is stored in an apparatus for displaying a character or an image.
A technique for measuring a brain activity of a person viewing a video and analyzing acquired data to estimate a line segment in the video perceived by the viewer is discussed in Yoichi Miyawaki et al. “Visual image reconstruction from human brain activity using a combination of multi-scale local image decoders”, Neuron, 60, 915-929 (2008). As discussed in this document, a nerve cell responding to a specific line segment in a video which is being viewed is present in the visual cortex of a human cerebrum. For example, in a primary visual cortex, the nerve cells are regularly arranged depending on visual fields of which the nerve cells take charge respectively. By measuring a neural activity of the primary visual cortex of a person viewing a video through functional magnetic resonance imaging, it is possible to estimate any position in the visual field in which an image of any line segment is displayed.
In the technique discussed in Japanese Patent Application Laid-Open No. 2004-191628, it did not estimate nothing about the movie factor which had influences on the organism-specific information, such as brain waves, a respiration, a pulse, blood pressure of viewer. For this reason, a video which does not need to be controlled is controlled in the same manner in addition to a video to be controlled. Consequently, an amount of information is unnecessarily reduced. As a result, there is an issue in that the quality of a video is unnecessarily deteriorated.
In the technique discussed in Yoichi Miyawaki et al. “Visual image reconstruction from human brain activity using a combination of multi-scale local image decoders”, Neuron, 60, 915-929 (2008), it is possible to estimate sensory information of a viewer. However, no control is applied to a video being viewed based on the sensory information, and thus, the influence on the viewer cannot be controlled.